<HTML><HEAD><TITLE>update(+Map0, ++Key, ?Value, -Map)</TITLE>
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<H1>update(+Map0, ++Key, ?Value, -Map)</H1>
Update the value corresponding to a key in a map.
<DL>
<DT><EM>Map0</EM></DT>
<DD>A map
</DD>
<DT><EM>Key</EM></DT>
<DD>A key to update
</DD>
<DT><EM>Value</EM></DT>
<DD>The value corresponding to Key
</DD>
<DT><EM>Map</EM></DT>
<DD>The map after updating
</DD>
</DL>
<H2>Description</H2>
	<P>
	If the key Key already exists in the map Map0, then this predicate
	updates the corresponding value to be Value.  The resulting map is
	Map.
	</P>
	<P>
	This predicate should only be called with maps created by other
	predicates from the map module.
	</P>
	
<H3>Fail Conditions</H3>
Fails if Key does not appear in Map0.
<H3>Resatisfiable</H3>
no
<H2>See Also</H2>
<A HREF="../../lib_public/m_map/det_update-4.html">det_update / 4</A>, <A HREF="../../lib_public/m_map/insert-4.html">insert / 4</A>, <A HREF="../../lib_public/m_map/det_insert-4.html">det_insert / 4</A>, <A HREF="../../lib_public/m_map/set-4.html">set / 4</A>
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